In both these great novels by Jane Austen, I would argue that the female characters are driven by a desire for love and financial security. Sexual desire is not expressed, nor is it a driving factor. In fact, the expression of sexual desire in a novel would have been considered incredibly scandalous in Austin's time.
In Pride and Prejudice, the Bennet sisters are to be faced with destitution after their father's eventual death if at least one sister does not marry well. In spite of this fact and its urgency, both Jane and Elizabeth Bennet are driven by a desire to find real love. Jane falls in love with Mr. Bingley not for his money but for his character. Similarly, Elizabeth proves that she would turn down a marriage proposal that could provide financial security for the family on the basis of a lack of love.
In Sense and Sensibility, the Dashwood sisters are also faced with financial hardship. While both girls's stories are driven by love and finding their "happily ever afters," sexual desire does not come into the equation—or if it does, we as the readers are certainly not told about it.